/***************************************************************************
 * Bytecode Viewer (BCV) - Java & Android Reverse Engineering Suite        *
 * Copyright (C) 2014 Konloch - Konloch.com / BytecodeViewer.com           *
 *                                                                         *
 * This program is free software: you can redistribute it and/or modify    *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation, either version 3 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
 ***************************************************************************/

package the.bytecode.club.bytecodeviewer.api;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.MethodNode;
import the.bytecode.club.bytecodeviewer.util.SleepUtil;

/**
 * @author Konloch
 * @since 6/27/2021
 */
public class ASMUtil
{
    /**
     * Creates a new ClassNode instances from the provided byte[]
     */
    public static ClassNode bytesToNode(byte[] b)
    {
        ClassReader cr = new ClassReader(b);
        ClassNode cn = new ClassNode();
        try
        {
            cr.accept(cn, ClassReader.EXPAND_FRAMES);
        }
        catch (Exception e)
        {
            cr.accept(cn, ClassReader.SKIP_FRAMES);
        }
        return cn;
    }

    /**
     * Writes a valid byte[] from the provided classnode
     */
    public static byte[] nodeToBytes(ClassNode cn)
    {
        final ClassWriter cw = new ClassWriter(0);

        try
        {
            cn.accept(cw);
        }
        catch (Exception e)
        {
            e.printStackTrace();

            SleepUtil.sleep(200);

            cn.accept(cw);
        }

        return cw.toByteArray();
    }

    public static MethodNode getMethodByName(ClassNode cn, String name)
    {
        for (MethodNode m : cn.methods)
        {
            if (m.name.equals(name))
                return m;
        }

        return null;
    }
}
